In the cable TV industry, television signals are typically transmitted to subscribers via a coaxial cable network. In particular, a typical coaxial cable includes an elongate center conductor surrounded by a dielectric material, which, in turn, is surrounded by a tubular outer conductor. A typical coaxial cable also includes a protective plastic jacket surrounding the outer conductor.
In a typical coaxial cable network it is often necessary to form a connection between adjacent sections of the coaxial cable, or between the coaxial cable and associated equipment, such as amplifiers, etc. It is important that these connections establish low resistance electrical contact and have high mechanical integrity to ensure proper transmission of the signal over the service life of the network.
A connector is commonly used for joining two sections of coaxial cable, or for terminating a coaxial cable for coupling to electronic equipment. A typical connector includes a body portion secured to the cable end and is threaded to allow connection to electronic equipment or to a corresponding mating body portion secured to an adjacent cable end.
A typical connector has respective clamping members that grip the center and outer conductors, respectively, to establish electrical and mechanical contact to the conductors. The outer conductor is gripped by a pair of inner and outer connector clamping members. The inner clamping member is typically a rigid metal sleeve inserted into the interior of the tubular outer conductor. The outer clamping member includes a swaging collar to firmly grip the tubular outer conductor of the coaxial cable against the inner metal sleeve.
To permit insertion of the inner sleeve of the connector into the cable end underlying the outer conductor, it is first necessary to remove a portion of the dielectric material from between the center and outer conductors. It is also necessary to remove a portion of the plastic jacket covering the outer conductor to allow the outer clamping member to make the proper mechanical and electrical connection with the outer conductor.
Conventional core drilling tools are typically used for removing the portion of dielectric material from between the center and outer conductors to allow the insertion of the inner metal sleeve. Such core drilling tools typically include a fluted drill bit with a central bore therethrough to receive the center conductor. The bit has a sharpened leading edge and is rotated as it is inserted into the dielectric material of the coaxial cable to thereby sever and remove a portion of the dielectric material. See, for example, U.S. Pat. No. 5,023,995 to Kaplan; U.S. Pat. No. 4,459,881 to Hughes, Jr.; U.S. Pat. No. 4,345,375 to Hayward; and U.S. Pat. No. 1,567,812 to Ober et al.
Tools are also available for stripping away a desired portion of the protective plastic jacket from the outer conductor of the coaxial cable as shown, for example, in U.S. Pat. No. 5,105,542 to Nakajima et al. and U.S. Pat. No. 4,729,268 to Morrow. Such a tool typically includes a cylindrical housing serving as a handle for grasping by a user and for mounting a cutting blade. The housing may also carry a mandrel that is inserted into the coaxial cable to support the outer conductor as the tool is rotated and the desired jacket portion is removed by the cutting blade. The housing of the tool may also have a threaded end so that it can be removably secured to an associated core drilling tool as disclosed, for example, in U.S. Pat. No. 4,459,881 to Hughes, Jr. and U.S. Pat. No. 4,729,268 to Morrow.
A conventional core drilling tool removes the bulk of the dielectric material from within the cable. Unfortunately, however, a thin residue or film of the dielectric material typically remains on the inside surface of the outer conductor as disclosed in U.S. Pat. No. 4,379,665 to Hendershot et al. This residue, in turn, may be trapped between the inside surface of the outer conductor and the inner sleeve of a connector. Over time, this residue may soften and migrate from the conductor surface thereby causing the clamping members to loosen. Accordingly, the mechanical strength of the connector is reduced and the connection may separate.